Two main theoretical approaches have been put forward to explain individual differences in life satisfaction: top-down (i.e., personological) and bottom-up (i.e., situational). The authors examine the relative merit of these 2 approaches and the psychological processes underlying top-down models. Consistent with a top-down approach, meta-analytic findings indicate that Neuroticism, Extraversion, Agreeableness, and Conscientiousness are related to both various domain satisfactions and life satisfaction; however, consistent with a bottom-up approach, domain satisfactions are strongly linked to life satisfaction but only weakly linked to each other. Path analyses based on meta-analytic estimates did not support a simple "direct-effects" top-down model but supported both (a) a temperament-based top-down model and (b) an integrative model that incorporates the direct influence of domain satisfactions on life satisfaction.